Note 12 - Equity Offerings (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	Jul. 23, 2023	Sep. 30, 2023	Sep. 30, 2023	Mar. 18, 2022
Warrants Issued in Registered Direct Offering [Member]
Other Nonoperating Expense		$ 700	$ 700
Warrants Issued in Registered Direct Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	23,809,524
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.42
Warrants and Rights Outstanding, Term (Year)	5 years
Proceeds from Issuance of Common Stock	$ 2,900
The 2022 ATM Offering [Member]
Stock Offering Agreement, Maximum Share Value				$ 100,000
Stock Offering Agreement, Commission, Percent				3.00%
Stock Issued During Period, Shares, New Issues (in shares)		78,600	433,672
Proceeds from Issuance of Common Stock		$ 25	$ 227
Common Stock Issued in Registered Direct Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	23,809,524
Proceeds from Issuance or Sale of Equity	$ 10,000
Proceeds from Issuance of Warrants	7,100
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 1,000